Simple Harmonic Motion:

This is a to and fro periodic motion of a particle in which:

(i) acceleration is proportional to the displacement from the mean position.

(ii) Acceleration is always directed towards a fixed point that is the mean equilibrium location.

 It may be represented by an expression with a periodic function as sine or cosine.

       x = X sin ωt

here X is the amplitude.

Diagrammatically it might be represented as illustrated in Figure 1.

While            ωt = 0, π           or   2π  ⇒ x = 0

While           ωt = π/2 ,    or x = X